Structural Features of the HlyIIR Operator of Bacillus cereus sensu lato

One of the central problems in molecular biology is to establish the mechanism of DNA-protein recognition. A promising model for elucidating the subtle processes of recognition is to study individual stages occurring during specific interaction of the regulatory protein with the operator. Determination of the structure of DNA and nucleotides involved in the interaction of the operator with the repressor allows us to elucidate the pathways of transcriptional regulation of gene expression. Analysis of the regulatory mechanisms of expression of genes encoding bacterial toxins allows us to understand the options for suppressing the toxin genes expression, which will ultimately ensure the creation of a system of regulated synthesis of bacterial toxins. Being study the role of the spatial structure and individual nucleotides of the operator region of the Bacillus cereus hlyII gene in the interaction with the transcriptional regulator HlyIIR, the regions of the operator region of hlyII gene that are essential for the interaction with the HlyIIR repressor were determined. The efficiency of the specific interaction of the HlyIIR repressor with its operator was determined depending on its DNA spatial structure. Using synthetic oligonucleotides with substitutions of individual nucleotides specific nucleotides of the operator were identified that ensure effective specific interaction with the repressor. Thus, changes in the profiles of the efficiency of DNA-protein recognition depending on the structure of the operator were shown.